 			(set-of [[g_2 2] [m_1 1]]
 				[g_2 (objects ctx-2)
 				 m_1 (attributes ctx-1)]))]
-    (make-context new-objs new-atts new-inz)))
+    (make-context-nc new-objs new-atts new-inz)))
 
 (defn context-product
   "Computes the context product of ctx-1 and ctx-2, that is

	inz (incidence ctx)
	prime (memoize (partial attribute-derivation ctx))]
    (set-of [g m]
	    [g obj
	     m att
	     :when (and (not (inz [g m]))
			(forall [n att]

  (for [objs (context-extents ctx)]
    [objs, (object-derivation ctx objs)]))

;;; Common Operations with Contexts

(defn dual-context
  "Dualizes context ctx, that is $(G,M,I)$ gets $(M,G,I^{-1})$."
